Vehicle for use in planetary exploration

ABSTRACT

A self-propelled vehicle particularly suited for use in traversing hostile terrain. The vehicle is characterized by a plurality of mutually independently operable propulsion units, each including an extended leg coupled with the frame of the vehicle for rotation about an axis transversely related thereto and supported by a steerable pedestal having operational attributes of both a wheel and an endless track and employable for propelling the vehicle along a given surface, through a selectively operable power train functioning to drive the leg in rotation about its axis and/or activating the pedestal in a wheel-driven and/or track-laying mode of operation.

United States Patent 1191 Fletcher et al. [4 1 May 1., 1973 VEHICLE FORUSE IN PLANETARY 2,361,165 10/1944 Arthur ..305/39 x EXPLORATION [76]Inventors: James C. Fletcher, Administrator of r Examufer Ben-lamm Hershthe National Aeronautics and Space Asslstam Exammer Pekar Administrationwith respect to an Attorney-John R. Mannmg, Monte F. Mott andWilinvention of; Edward Hryniewiecki, fred Gnfka Sherman Oaks, Calif.[57] ABSTRACT [22] F1led: May 17, 1971 If n d h l t l l t d f A se-prope e ve 10 e par 1cu ary su1 e or use in [21] Appl' 144l39traversing hostile terrain. The vehicle is characterized 1 by aplurality of mutually independently operable [52] US. Cl. ..l80/6.5,l80/7 R, 180/8 A, propulsion units, each including an extended leg cou-180/9.2 R, l80/9.5, 180/41, 305/35 EB, pled with the frame of thevehicle for rotation about 3 3 an axis transversely related thereto andsupported by a [5 1] Int. Cl. steerable pedestal having operationalattributes of of Search R, 9.46, both a wheel and an endless [rack andemployable for R, 8 R, 8 43 45, propelling the vehicle along a givensurface, through a selectively operable power train functioning to drive[56] References Cited the leg in rotation about its axis and/oractivating the UNITED STATES PATENTS pedestal in a wheel-driven and/ortracklaying mode of operation. 2,172,177 9/l939 Rose ..l80/45 3,348,51810/1967 Forsyth et al. ..180/8 A X 9 Claims, 19 Drawing Figures PatentedMay' l, 1973 4 Sheets-Sheet 1 EDWARD. HRYN/EW/EC/(l A 77'ORNEVS PatentedMay 1, 1973 4 Sheets-Sheet 2 EDWARD H/PYN/EW/ECK/ ATTORNEYS Patented May1, 1973 3,730,287

4 Sheets-Sheet 5 EDWARD HRYN/EW/ECK/ M! INVENTOI? A TTORNEKS PatentedMay 1, 1973 3,730,287

a I A R EDWARD HRVN/EW/ECK/ WM W A TTORNEKS' 1 VEIIICLE FOR USE INPLANETARY EXPLORATION ORIGIN OF INVENTION The invention described hereinwas made in the performance of work under a NASA contract and is subjectto the provisions of Section 305 of the National Aeronautics and SpaceAct of 1958, Public Law 85- 568 (72 Stat. 435; 42 USC 2457).

BACKGROUND OF THE INVENTION 1. Field of the Invention The inventionrelates to self-propelled vehicles and more particularly to aself-propelled vehicle having the attributes of a walking vehicle, awheeled vehicle and a track-laying vehicle.

2. Description of the Prior Art Currently, numerous types of vehiclesare employed in traversing rugged and generally hostile terrain. Amongsuch vehicles are those commonly referred to as walking vehicles,wheeled vehicles and track-laying vehicles.

Each of these vehicles is particularly suited for use in a givenenvironment wherein the characteristics of given surfaces generally areknown. For example, where an encountered surface is quite soft,track-laying vehicles function quite satisfactorily, walking vehicles,on the other hand, are particularly suited for use in more ruggedterrain, having good load-supporting characteristics, while wheeledvehicles tend to be more maneuverable and normally are of less mass,made possible through simplistic construction. Consequently, difficultyoften is encountered in designing a single type of vehicle for use in avariety of environments, as may occur in space exploration, wherein thesurface characteristics vary widely from a soft planar surface to asurface characterized by rugged rocks and large fissures and bearinglayers of motion inhibiting materials having textures ranging between apowder and extremely coarse aggregate.

Therefore, there currently exists a need for a practical, self-propelledvehicle which is highly maneuverable, readily is employable innegotiating slopes, of both a positive and a negative nature, traversingsoft and smooth surfaces as well as hard aggregate-bearing surfaces,crossing large fissures, and is capable of maintaining positionstability while being economic to manufacture and deliver to surfaces ofselected planetary bodies, and employed in various combinations of modesof locomotion.

OBJECTS AND SUMMARY OF THE INVENTION It is therefore an object of theinstant invention to provide an improved vehicle.

It is another object to provide an improved, selfpropelled vehiclecapable of being propelled through a flexible mode of.locomotion. t

It is another object to provide an improved, selfpropelled vehiclehaving the attributes of a walking vehicle, a wheeled vehicle and atrack-laying vehicle.

It is another object to provide a vehicle having a propulsion systemincluding a plurality of independently operable drive units, each unithaving the attributes of a walking leg", a wheel, and an endless track.

It is another object to provide for use in vehicles of the type employedin traversing rugged terrain, a propulsion system including a segmentedleg supported by a steerable pedestal having a load-supporting terminalcomponent circumscribed by an endless rim.

These and other objects and advantages are achieved through a vehicleincluding a propulsion system coupled with a load-supporting frame andincluding a plurality of drive units, each unit having a leg extendedfrom the frame and supported for rotation about a first axistransversely related to the frame, and a steerable pedestaldependingfrom the leg provided with a rotatable hub supported forrotation about a second axis extending parallel to saidfirst axis andhaving a plurality of radially extended spokes circumscribed by anendless rim supported for circulation alongan endless pathcircumscribing the distal ends of the spokes.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation of avehicle supported by a plurality of drive units which embody theprinciples of the instant invention.

FIG. 2 is a perspective, schematic view collectively depicting variouspositions which may be assumed by each of the drive units during theoperation of the vehi cle shown in FIG. 1.

FIG. 3 is a perspective view, on an enlarged scale, of a leg andpedestal which together function as a drive unit.

FIG. 4 is a fragmented, perspective view, on an enlarged scale, of apedestal employed bythe drive unit il lustrated in FIG. 3.

FIG. 5 is a partially sectioned, schematic view of the drive unit shownin FIG. 3.

FIG. 6 is a schematic view of the vehicle illustrated in FIG. I,depicting a control circuit employable by an operator in controlling theoperation of the vehicle shown in FIG. 1.

FIGS. 7 and 8 are similar exemplary views collectively depictingsuccessive positions assumed by the drive units of the vehicle of FIG. 1as the vehicle is caused to traverse a rugged terrain having non-uniformsurface characteristics.

FIGS. 9A through 9E collectively illustrate an operational sequence forthe vehicle of FIG. 1 as it is caused to traverse a crevice.

FIGS. 10A through 10F collectively illustrate an operational sequencefor the vehicle of FIG. 1 as .it is caused to traverse a severelyinclined surface.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawingswherein like reference characters designate like or corresponding partsthroughout the several views, there is shown in FIG. 1 a vehicle 10which embodies the principles of the instant invention.

As shown, the vehicle 10 includes a load-bearing frame 12 which servesas a traveling support for selected equipment of a general nature,designated 14, and a vehicle operator 0 seated thereon and supportedthrough suitable structural components, generally designated 16.

The vehicle 10 is, in operation, controlled through an electricalcircuit 17, FIG. 6, and coupled with a suitable control panel, generallydesignated I8. The control panel 18 preferably includes a plurality ofswitches, levers and buttons suited to be manipulated by the operationfor purposes of controlling the operation of the vehicle as it traversesa given surface of terrain of either a celestial or terrestrial origin.It is to be understood, however, that while an electrical circuit isshown in the drawings, the particular control mechanism employed incontrolling the operation of the vehicle 10 can be varied as is founddesirable for a given set of operational parameters.

The vehicle 10 is supported and propelled through a plurality ofappropriately situated drive units, generally designated 20. Each of thedrive units 20 is provided with a tubular leg 22 having angularlyrelated segments. The leg 22 includes a base segment 24 pivotallycoupled with a frame 12 of the vehicle 10. A suitable bearing couplingmounted in a closed housing 26 preferably is employed for this purpose.Since the bearing coupling and closed housing 26 can be of any suitabledesign, a detailed description thereof is omitted in the interest ofbrevity. However, it is to be understood that the bearing coupling isfixed to the frame 12 through a judicial use of studs, welds and thelike. Furthermore, the bearing coupling is provided with a bearing race28 associated with the housing 26, FIG. 5, which concentrically receivesan end portion of the base segment 24 in order to join the leg 22 withthe frame 12 so that the leg 22 is supported for pivotal displacementabout an axis C-C, FIG. 5, transversely related to the frame 12.

Orthogonally related to the base segment 24 of a leg 22 there is anintermediate segment 30 which is welded or otherwise coupled with thebase segment 24 and becomes an integral part thereof. At the distal endof the intermediate segment 30, there is a pedestal 32 rotatably coupledwith the segmented leg 22 through a coupling including a thrust bearing34 of a suitable design. The pedestal 32 preferably is related to theintermediate segment 30 and the base segment 24 of the segmented leg 22in a manner such that its longitudinal axis, designated ZZ, parallelsthe axis CC of the base segment 24 and is normally related to thelongitudinal axis of the intermediate segment 30, designated YY in FIG.5.

As a practical matter, the pedestal 332 is so coupled with theintermediate segment 30, through the thrust bearing 34 as to permit itto be rotated about the axis YY, however, since the specific manner inwhich the pedestal 32 is coupled with the intermediate segment 30 can bevaried as desired, for a selected use in a given environment, a detaileddescription thereof is omitted in the interest of brevity.

The pedestal 32 includes a housing 38, also ofa tubular configuration,and supports at its outermost end a load-bearing terminal component 40.The terminal component 40 is of a triangular configuration and possessesthe combined attributes of a foot, a wheel, and an endless track.Through the use of the terminal component 40, the vehicle 10 is renderedcapable of coping with the total spectrum of surfaces normallyencountered in traversing terrain ofa variable nature.

As best illustrated in FIG. 4, the terminal component 40 includes a hub42, supported by a suitable bearing 43, FIG. 5, suitably mounted aboutthe distal portion of the housing 38 of the pedestal 32. The hub 42includes a plurality of radiating, arm-like spokes 44, preferably spacedapart about its periphery. The terminals of the spokes 44 are spaced atequidistances from the axis Z-Z and support a plurality of sprocketassemblies 46. Each of the sprocket assemblies 46 is of a suitabledesign and is coupled with a given spoke 44 through a bearing sleeve 48.The bearing sleeves 48 include bearings 49, FIG. 5, which, in turn,serve to support an axle 50 for rotation about axis XX. At eachend -ofthe axle 50 there is a sprocket wheel 52 fixed thereto. However, varioustypes of sprockets and mountings for sprockets can be employed equallyas well.

About the thus provided plurality of sprocket wheels 52 there is trainedand endless chain 54, of a track-like configuration, which meshes withthe teeth of the sprocket wheels 52 in order to establish a drivingrelationship therebetween. Hence, it can be appreciated that by drivingone of the sprocket assemblies 46, in either direction about the axis' xx, the chain 54 is caused to progress in circulation along an endlesspath circumscribing the distal ends of the spokes 44 of the hub 42.

Mounted on the chain 54 there is an endless, flexible tire 56. The tire56 includes a body preferably formed of a resilient material such as anexpanded metal mesh which is both durable and resilient. Since, inpractice, metal mesh permits dust, mud, and the like readily to passtherethrough without unduly burdening the tire, mesh can be employedwithout a covering. However, a suitable fabric covering, designated 57,preferably is employed in covering the mesh.

Since the particular manner and materials employed in fabricating thetire 56 are matters of convenience, a detailed description thereof isomitted in the interest of brevity. It is, however, to be understoodthat the tire 56 is flexible enough to be shaped to a triangularconfiguration, and when in contact with the surface of the terrain issufficiently resilient for forming a substantially flat, elongatedfootprint and, in effect, serves as a segment of a track similar to thatoften provided for so-called track-laying vehicles.

When compared to a circular wheel of an equivalent diameter and treadwidth, the footprint established by the tire 56 reduces ground pressureby a factor of approximately 2.5. The resulting distribution ofgroundloading, when employing the terminal component 40, is particularlysuited for traveling over terrain having relatively poor load-bearingcharacteristics.

The chain 54 is, in operation, driven through a chainand-sprocket driveunit, generally designated 58. As currently employed, thechain-and-sprocket drive unit 58 includes a driving sprocket wheel 60rigidly coupled to an output shaft 62, supported by a suitable bearing63, FIG. 5, and an endless chain 64 trained about a driven sprocketwheel 66 fixed to an axle 50 of one of the sprocket assemblies 46.Accordingly, it can be appreciated that as rotation is imparted to theoutput shaft 62 the chain 64 is driven to impart rotation to thesprocket wheel 66 for thus imparting rotation to the axle 50. As theaxle 50 is advanced, the chain 54 and the tire 56 also are advancedabout the sprocket assemblies 46 supported by the distal ends of thespokes 44. Thus the tire 56 is driven in circulation about the sprocketassemblies 46.

It is important to notethat the hub 42 is supported for rotation aboutan axisdesignated ZZ, FIG. 5, hence, this axis serves as an axis ofrotation for the spokes 44. Where unrestricted rotation of. the hub 42,about the axis Z-Z is accommodated, in a so-called free wheeling mode,the terminal component 40 is permitted continuously to reorient itsposition relative to the surface of the terrain engaged thereby. Thus,the terminal component 40 is capable of maintaining operative engagementwith a surface of uneven terrain as it is afforded an opportunity toundergo a rocking motion about the axis Z-Z. Such capability is, for thesake of convenience, termed articulation.

Each of the drive units is provided with a segmented power train 70,FIG. 5, through which rotation is imparted to the sprocket assemblies46, about the axis XX, the hub 42, about the axis Z-Z, the pedestal 32,about the axis Y-Y,"and the leg 22, about the axis C-C.

The power train 70 schematically is illustrated in FIG. 5 for the sakeof simplicity. However, it is to be understood that the power train 70,including its various components, is fabricated in a manner consistentwith known machine design and fabrication techniques. Therefore, adetailed description of the specific structural components employed inthe power train 70 is omitted in the interest of brevity.

Preferably, the power train 70 includes a prime mover or intermittentlyoperated motor 72 seated within the housing 38 of the pedestal 32. Themotor is energized by a portable source74 of electrical potentialcoupled therewith. The motor 72 is a(Direct Current) D.C. motor havinghigh-torque characteristics and is provided with a pair of coaxiallyrelated input shafts 76 and 78 for the power train 70. These shaftspreferably are integrated and simultaneously provide an input from themotor 72.

In practice,the :input shaft 76 is coupled with a dual clutch assembly80. This assembly includes a first clutch coupling 82, and anindependently operable second clutch coupling 84. The coupling 82 servesto couple the input shaft 76 with the output shaft 62, while the secondclutch coupling 84 serves to couple the shaft 76 with a suitabledrive-ring 86 rigidly fixed to the hub 42 in a concentric relationshipwith the output shaft 62. The drive-ring 86 is of any suitable designwhich permits the hub 42 to be'driven thereby.

The clutch assembly 80 can be varied as is found desirable for givenoperational parameters. However, the clutch couplings 82 and 84preferably include displaceable friction surfaces which function quitesatisfactorily for this purpose and are employed in a manner consistentwith known principles of machine design.

It is to be understood, however, that in the event the first clutchcoupling 82 is engaged, a driving coupling is established between theshaft 76,0f the motor 72, and

the output shaft 62, whereupon the chain-and-sprocket drive unit 58 isactivated for causing the tire 56 to cir Accordingly, it shouldappreciated that the terminal component 40 is, in operation, selectivelydriven in modes of operation wherein the tire 56 is caused to circulateabout the distal ends of the spokes 44 and/or the hub 42 simultaneouslyis rotated about the axis Z- 2. Through a selective employment of theclutch assembly 80, the terminal component 40 can be'operated in thesemodes in sequence or, if desired, concurrently.

The input shaft 78, FIG. 5, is coupled with an output drive shaft 88through a selectively operable clutch assembly 90 of a design somewhatsimilar to the clutch assembly 80. It is to be understood, however,'thatthe clutch assembly includes a single clutch component 92, preferably afiction clutch component, which serves selectively to couple the driveshaft 88 with the shaft 78 of the motor 72. I

The drive shaft 88 is supported within the housing 38 of the pedestal 32for free rotation about the axis Z-Z, by a suitable bearing 94,andconcentrically supports a first bevel Gear 96 of a bevel gearcoupling 97. The bevel gear 96 is meshed with a bevel gear 98 supportedfor rotation about the axis Y-Y at the adjacent end of a drive shaft100. a practical matter, the drive shaft 100 is supported in aconcentric relationship within the segment 30 through aplurality ofsuitably supported bearings, including bearings 102 and 104 mountedwithin the segment 30. Hence, it is to be understood that through theclutchassembly 90, the bevel gear coupling 97 serves to impart a drivingrotation to the shaft 100 as it is supported for rotation by thebearings 102 and 104.

At the end of the shaft 100 opposite the bevel gear 98, there isprovided another bevel gear 106 of a bevel gear coupling 107. This bevelgear is meshed with a bevel gear 108 rigidly fixed to an anchor shaft110 welded or otherwise rigidly secured to the frame 12 within thebearing housing 26 in a manner such that the shaft 110 is supportedagainst rotation relative to the axis C-C and the frame 12 of thevehicle 10. It should therefore be apparent that the bevel gear coupling97 functions as an input coupling while the bevel gear coupling 107functions as an output coupling for the power train 70. j

It is important to note that the clutch assemblies and are each providedwithactuating means of any suitable design, including electromagnets andthe like which function quite satisfactorily for this purpose. Since theclutch actuators are well known and can be varied as is found desirable,a detailed description of theactuators for theassemblies 80 and 90 isomitted in the interest of brevity. However, it is to be understood thatsolenoids, not1 shown, preferably are employed, v

although other types of actuators can be employed equally as well.

As illustrated in FIG. 5, the shaft 110 concentrically supports anexpandable friction brake 112, while the shaft similarly supports anexpandable friction brake 114. The brake 112 is configured to expandinto locking engagement with a braking surface, not designated,circumscribing the internal surface of the base segment 24 of thesegmented leg 22, while the brake 114 is configured to expand intolocking engage ment with an annular braking surface, also not designate,circumscribing the internal surfaces of the. intermediate segment 30.Thus, the brakes I12 and 1 l4 act to inhibit relative rotation betweenthe associated shafts and the segments of the leg 22. While not shown,it will be appreciated that, where desired, the drive shaft 88 can beprovided with an expandable brake similar to the brakes 112 and 114 forprecluding rotation of the pedestal 32.

As should readily be apparent from a cursory examination of FIG. 5, inorder to impart rotation of the segmented leg 22 and the associatedpedestal 32 relative to the axis C-C, a coupling of the clutch assembly90 is effected, 'whereupon the input coupling 97 is driven by the motor72. As the motor 72 drives the coupling 97, the gear 106 of the coupling107 is advanced about the periphery of the bevel gear 108. Thus the leg22 is angularly displaced about the axis C-C, as the shaft 110 isretained in a stationary position, relative to the frame 12, in order toprovide a reactive torque therewith.

In the event it becomes desirable to rotate the pedestal 32 about theaxis YY, the brakes 112 and 114 are expanded into locking engagementwith the adjacent braking surfaces of the segments 24 and 30 for therebyfreezing the shaft 100 against rotation. With the shaft 100 frozenagainst rotation, an engagement of a clutch assembly 90 causes the bevelgear 96 of the coupling 97 to advance about the periphery of the bevelgear 98 for thus angularly displacing the pedestal about the axis YY.

In view of the foregoing, it should readily be apparent that byselectively employing the clutch assemblies 80 and 90 in conjunctionwith the brakes 112 and 114, selective rotation can be imparted to thepedestal 32 and/or to the segmented leg 22 of the drive unit 20, whileconcurrently therewith, the tire 56 can be circulated about the sprocketassemblies 46 and/or the hub 42 driven in rotation about the axis ZZ.Thus the drive unit 20 can be caused to function in a walking mode, asteerable rolling mode and a steerable tracklaying mode.

It is important to understand that steering of the circulating tires 56is achieved through a rotation of the pedestal 32. Furthermore, thedrive units 20 can be operated independently of each of the other units.Accordingly, the control circuit 17 includes suitable circuit leadscoupling the control panel 18 with the selectively operable componentsof each of the drive units 20, as illustrated in FIG. 6, in order toimpose selective gain control over the operation of the vehicle byindependently controlling the operation of the units 20.

By employing the control circuit 17 and the panel 18, the vehicle 10 canbe caused to traverse various types of terrains with the drive units 20oriented in selected orientation relative to the frame 12 of the vehicle10 and functioning in multiple modes of operation, simultaneously or ina selected sequence. For example, as shown in FIGS. 7 and 8, the legs 22of the drive units 20 are rotatably advanced from the positionsillustrated in FIG. 1 while the drive units 20 continue to function inmodes dictated through a manipulation of the panel 18.

crossing of large crevices. Since each of the units 20 is subject toindependent control, the vehicle 10 initially is advanced to the edge ofthe crevices and the drive units 20 sequentially rotated about the axisC-C for successively advancing the drive unit to the opposite side ofthe crevice in a sequence which effects a. stepping across the crevicein a manner consistent with the operation of a walking vehicle.-

FIGS. 10A through 10E collectively. illustrate one manner in which thevehicle 10 can be utilized in climbing to a plateau of a rather severelyinclined surface. In such instances, the tires 56 are caused tocirculate the sprocket assemblies 46, the hub 42 is rotated about theaxis ZZ while the segmented leg and pedestal of the drive unit arerotated about the axis C- C in a manner such that the vehicle 10 isafforded an opportunity to climb the surface of the obstruction bystepping the terminal components 40 into engagement with the face of theobstruction while driving the tire 56 vin circulation about the sprocketassemblies until such time as rotary motIon is desired for the hubs 42so that the vehicle 10 is afforded an opportunity to climb the face ofthe obstruction.

OPERATION It is believed that in view of the foregoing description, theoperation of the device will be readily understood and it will bebriefly reviewed at this point.

An operation. 0 seated upon the vehicle 10 is supported access to thepanel 18 for purposes of steering the vehicle 10 along a given surface,regardless of its load-bearing characteristics, being traversed by thevehicle. Through a selected manipulation of switches and the like, notdesignated, the operator 0 is afforded an opportunity to control thedrive units 20 of the vehicle 10.

When the vehicle 10 is operating in a wheel-driven or track-laying mode,the brakes 112 and 114 normally are in an activated state, wherebyrotation of the leg 22 and the pedestal 32 is precluded.

Preferably, the first clutch assembly 82 of the clutch assembly isengaged for causing the shaft 62 to drive the chain-and-sprocket driveunits 58 in a manner such that the driven sprocket wheel 66 impartsrotation to the axle 50 for thus driving the tire 56 in circulationabout the sprocket assemblies 46 supported at the distal end of thespokes 44 whereby the vehicle 10 is caused to operate in a crawling ortrack-laying mode of operation. Since the second clutch coupling 84 isdisengaged, each of the terminal components 40 is afforded a rockingmotion or permitted to articulate in order to accommodate itself to theinclination of surface being traversed.

In the event it becomes desirable to drive the terminal components 40 ofany or all of the drive units 20 in rotation in-a manner such that theterminal component 40 functions as. a ffwheel, the second clutchcoupling 84 is engaged'whereupon the shaft 76 serves to drive the hub 42in rotation about the axis ZZ through the drive-ring 86.

In the event it becomes desirable to steer or alter the direction inwhich the vehicle is traveling, regardless 0F whether the vehicle isoperating in a track-laying or wheeldriven mode, the pedestal 32 isdriven in rotation about the axis YY, through aselected energization ofthe motor 72, for thus redirecting the direction of travel for theterminal components 40 for appropriate drive units 20. In order toachieve desired rotation of the pedestal 32, the clutch assemblies 90 ofselected drive units are engaged while the brakes 112 and 1 14frictionally lock the shafts 110 and 100 to the concentrically relatedsegments of the leg 22. Hence, the bevel gear 96 is driven in circularmotion about the periphery of the bevel gear 98 for thus redirecting theaxis Z-Z so that the pedestal 32 i8 caused to rotate through a selectedangle about the axis Y-Y, whereupon the clutch assemblies are againdisengaged. Thus the direction of travel for the terminal components ofthe selected drive units is altered.

Should it become desirable to operate the vehicle 10 in a walking mode,the motor 72 is energized, the clutch assembly 90 is engaged, forthereby driving the coupling 97, with the brakes 112 and 114 having beenreleased, whereupon the leg 22, with its associated pedestal 32,isdriven in rotation about the axis C-C as the bevel gear advances aboutthe periphery of the bevel gear 108.

It is important to note that so long as the brake 112 is engaged withthe base segment 24 of the segmented leg 22 rotation of the segmentedleg about the axis C-C is precluded even though the shaft 100 isafforded rotation. Consequently, it is desirable to simultaneouslyengage and release the brakes 112 and 114 when operating the vehicle ina walking mode.

In view of the foregoing, it should readily be apparent that the vehicleof the instant invention provides a practical solution to the perplexingproblem of providing a vehicle which readily accommodates its operationto a hostile terrain through multiple modes of operation.

Although the invention has been herein shown and described in what isconceived to be the most practical and preferred embodiment, it isrecognized that departures may be made therefrom within the scope of theinvention, which is not to be limited to the illustrative detailsdisclosed.

What is claimed is:

l, A vehicle comprising:

A. a load supporting frame;

B. a plurality of legs extended from said frame, each leg being coupledat its base to said frame and supported for pivotal displacement about afirst axis of rotation transversely related to the frame; an:

C. a propulsion system for propelling said frame including a pluralityof pedestals coupled to the distal ends of said legs and supported forpivotal displacement about a second axis of rotation angularly relatedto said first axis of rotation, and a terminal component mounted on eachof said pedestals in supporting relation therewith includl. a rotatablehub and a plurality of angularly related arms radially extended from thehub and terminating at equidistances from a third axis of rotationangularly related to said first axis of rotation,

2. a plurality of sprockets, each being rotatably supported at thedistal end of one of said arms,

. 3. an endless rim including a flexible chain operatively meshed withsaid sprockets and a resilient body formed of An expanded meshcircumscribing the periphery of the component and supported foradvancement along an endless path circumscribing said second] axis ofrotation, and

. a selectively operable power train comprising a plurality ofelectrically energizable motors, each being supported within one of saidpedestals, and a selectively engageable clutch and brake systemincluding means for selectively coupling each of the motors with one ofsaid legs for driving the leg in rotation about said first axis ofrotation, means for selectively coupling each of said motors to one ofsaid pedestals for driving the pedestal in rotation about said secondaxis of rotation, means for selectively coupling each of the motors withone of the terminal components for driving the hub in rotation about thethird axis of rotation, means for selectively coupling each of saidmotors with one of said rims, and for advancing the rim along-said path.

2. A vehicle for traversing rough terrain comprising:

A. a load supporting frame;

B. a plurality of frame supporting legs, each leg being coupled at itsbase with said frame and supported for angular displacement about afirst axis of rotation, said first axis being transversely related tosaid frame; I

C. a propulsion system including,

1. a plurality of pedestals, each pedestal being coupled with the distalend of one of said legs and supportedfor rotational displacement about asecond axis of rotation, said second axis being coincident with thelongitudinal axis of symmetry of the leg to which the pedestal iscoupled and angularly related to the first axis of rotation, nd

2. a terminal component of a substantially triangular configurationsupported for rotation about a third axis of rotation, said third axisbeing coincident with the longitudinal axis, of symmetry of saidpedestal and angularly related to said second axis of rotation; and

D. a selectively operable drive system including an electricallyenergizable motor seated in each of said pedestals, and l. clutch meansfor selectively coupling each of said legs in driving relation with oneof said motors for driving the legs in rotation about said first axis ofrotation,

2. clutch means for selectively coupling each of said pedestals indriving relation with one of said motors for driving the pedestals inrotational dis placement about said second axis of rotation, and

3. clutch means for selectively coupling each of said terminalcomponents in driving relation with one of said motors for driving theterminal components in rotation about said third axis of rotation.

3. A vehicle for traversing relatively rough terrain comprising:

A. a load supporting frame;

B. a plurality of frame-supporting legs, each leg being coupled at itsbase with said frame and supported for rotation about a first axis ofrotation, said first axis being transversely related to said frame;

C. a propulsion system including,

1. a plurality of pedestals, each of said pedestals being coupled withthe distal end of one of said legs and supported for rotationaldisplacement about a second axis of rotation, said second axis beingangularly related to said first axis of rotation,

2. a terminal component of a substantially triangular configurationsupported for rotation about a third axis of rotation, Paid third axisbeing angularly related to said second axis of rotation; and

3. a selectively operable drive system including, a

' selectively energizable motor seated in each of said pedestals and adrive train extended through each of said pedestals and each of saidlegs, said drive train having included therein a selectively operableclutch and brake means for driving the leg through which it is extendedin rotation about said first axis of rotation, selectively operableclutch and brake means for driving the pedestal through which it isextended in rotational displacement about said second axis of rotation,and clutch and brake means for driving each of the terminal componentsin rotation about said third axis of rotation.

4. The vehicle of claim 3, wherein each of said legs is restrainedagainst displacement as the pedestal coupled therewith is driven inrotational displacement about said second axis of rotation.

5. The vehicle of claim 4, wherein the terminal components of eachpedestal include a circumscribing rim and means for advancing the rimabout the periphery thereof.

6. The vehicle of claim wherein the means for advancing the rim includesa chain-and-sprocket coupling.

7. The vehicle of claim 6, wherein said means for ad vancing the rimfurther includes additional clutch means for releasably coupling saidchain-and-sprocket with said drive means.

8. In a propulsion system for a vehicle, the improvement comprising:

A. a segmented leg including,

l. a base segment rotatably coupled with means defining a frame for thevehicle and supported for rotation about a first axis transverselyrelated to said frame, and 2. an intermediate segment rigidly coupledwith said base segment and angularly related thereto; B. a pedestalextended from said intermediate segment and supported for rotation aboutthe longitudinal axis thereof;

C. a terminal component operatively associated with said pedestal forpropelling the vehicle including, 1. a hub supported for rotationaldisplacement about a concentric axis coincident with an axis of rotationangularly related to saId longitudinal axis, 2. a plurality ofradiating, coplanar spokes extended from said hub, and 3. an endless rimcircumscribing said terminal component and mounted for advancement alongan endless path transversing the distal ends of said spokes; and D. aselectively operable, common drive means coupled with the leg, theterminal component, and the pedestal for se ectively imparting theretorotational displacement.

9. The improvement of claim 8 wherein the common drive includes:

A. an electrically energizable motor, supported in said pedestal, a pairof output shafts operatively associated with said motor;

B. a segmented power train extending from said pedestal, through saidleg to said frame, and clutch means for releasably coupling thesegmented power train with one output shaft of said pair of outputshafts;

C. a bifurcated power train, including a first and a second power trainseg'ment, operatively associated with the other output shaft of saidpair of output shafts; and

D. clutch means for releasably coupling a first power train segment withthe other output shaft of said pair, and clutch means for releasablycoupling the second power train segment with the other output shaft.

1. A vehicle comprising: A. a load supporting frame; B. a plurality oflegs extended from said frame, each leg being coupled at its base tosaid frame and supported for pivotal displacement about a first axis ofrotation transversely related to the frame; an: C. a propulsion systemfor propelling said frame including a plurality of pedestals coupled tothe distal ends of said legs and supported for pivotal displacementabout a second axis of rotation angularly related to said first axis ofrotation, and a terminal component mounted on each of said pedestals insupporting relation therewith including,
 1. a rotatable hub and aplurality of angularly related arms radially extended from the hub andterminating at equidistances from a third axis of rotation angularlyrelated to said first axis of rotation,
 2. a plurality of sprockets,each being rotatably supported at the distal end of one of said arms, 3.an endless rim including a flexible chain operatively meshed with saidsprockets and a resilient body formed of An expanded mesh circumscribingthe periphery of the component and supported for advancement along anendless path circumscribing said second axis of rotation, and
 4. aselectively operable power train comprising a plurality of electricallyenergizable motors, each being supported within one of said pedestals,and a selectively engageable clutch and brake system including means forselectively coupling each of the motors with one of said legs fordriving the leg in rotation about said first axis of rotation, means forselectively coupling each of said motors to one of said pedestals fordriving the pedestal in rotation about said second axis of rotation,means for selectively coupling each of the motors with one of theterminal components for driving the hub in rotation about the third axisof rotation, means for selectively coupling each of said motors with oneof said rims, and for advancing the rim along said path.
 2. a pluralityof sprockets, each being rotatably supported at the distal end of one ofsaid arms,
 2. a plurality of radiating, coplanar spokes extended fromsaid hub, and
 2. an intermediate segment rigidly coupled with said basesegment and angularly related thereto; B. a pedestal extended from saidintermediate segment and supported for rotation about the longitudinalaxis thereof; C. a terminal component operatively associated with saidpedestal for propelling the vehicle including,
 2. clutch means forselectively coupling each of said pedestals in driving relation with oneof said motors for driving the pedestals in rotational displacementabout said second axis of rotation, and
 2. a terminal component of asubstantially triangular configuration supported for rotation about athird axis of rotation, said third axis being coincident with thelongitudinal axis of symmetry of said pedestal and angularly related tosaid second axis of rotation; and D. a selectively operable drive systemincluding an electrically energizable motor seated in each of saidpedestals, and
 2. A vehicle for traversing rough terrain comprising: A.a load supporting frame; B. a plurality of frame supporting legs, eachleg being coupled at its base with said frame and supported for angulardisplacement about a first axis of rotation, said first axis beingtransversely related to said frame; C. a propulsion system including, 2.a terminal component of a substantially triangular configurationsupported for rotation about a third axis of rotation, Paid third axisbeing angularly related to said second axis of rotation; and
 3. Avehicle for traversing relatively rough terrain comprising: A. a loadsupporting frame; B. a plurality of frame-supporting legs, each legbeing coupled at its base with said frame and supported for rotationabout a first axis of rotation, said first axis being transverselyrelated to said frame; C. a propulsion system including,
 3. clutch meansfor selectively coupling each of said terminal components in drivingrelation with one of said motors for driving the terminal components inrotation about said third axis of rotation.
 3. a selectively operabledrive system including, a selectively energizable motor seated in eachof said pedestals and a drive train extended through each of saidpedestals and each of said legs, said drive train having includedtherein a selectively operable clutch and brake means for driving theleg through which it is extended in rotation about said first axis ofrotation, selectively operable clutch and brake means for driving thepedestal through which it is extended in rotational displacement aboutsaid second axis of rotation, and clutch and brake means for drivingeach of the terminal components in rotation about said third axis ofrotation.
 3. an endless rim including a flexible chain operativelymeshed with said sprockets and a resilient body formed of An expandedmesh circumscribing the periphery of the component and supported foradvancement along an endless path circumscribing said second axis ofrotation, and
 3. an endless rim circumscribing said terminal componentand mounted for advancement along an endless path transversing thedIstal ends of said spokes; and D. a selectively operable, common drivemeans coupled with the leg, the terminal component, and the pedestal forselectively imparting thereto rotational displacement.
 4. a selectivelyoperable power train comprising a plurality of electrically energizablemotors, each being supported within one of said pedestals, and aselectively engageable clutch and brake system including means forselectively coupling each of the motors with one of said legs fordriving the leg in rotation about said first axis of rotation, means forselectively coupling each of said motors to one of said pedestals fordriving the pedestal in rotation about said second axis of rotation,means for selectively coupling each of the motors with one of theterminal components for driving the hub in rotation about the third axisof rotation, means for selectively coupling each of said motors with oneof said rims, and for advancing the rim along said path.
 4. The vehicleof claim 3, wherein each of said legs is restrained against displacementas the pedestal coupled therewith is driven in rotational displacementabout said second axis of rotation.
 5. The vehicle of claim 4, whereinthe terminal components of each pedestal include a circumscribing rimand means for advancing the rim about the periphery thereof.
 6. Thevehicle of claim 5 wherein the means for advancing the rim includes achain-and-sprocket coupling.
 7. The vehicle of claim 6, wherein saidmeans for advancing the rim further includes additional clutch means forreleasably coupling said chain-and-sprocket with said drive means.
 8. Ina propulsion system for a vehicle, the improvement comprising: A. asegmented leg including,
 9. The improvement of claim 8 wherein thecommon drive includes: A. an electrically energizable motor, supportedin said pedestal, a pair of output shafts operatively aSsociated withsaid motor; B. a segmented power train extending from said pedestal,through said leg to said frame, and clutch means for releasably couplingthe segmented power train with one output shaft of said pair of outputshafts; C. a bifurcated power train, including a first and a secondpower train segment, operatively associated with the other output shaftof said pair of output shafts; and D. clutch means for releasablycoupling a first power train segment with the other output shaft of saidpair, and clutch means for releasably coupling the second power trainsegment with the other output shaft.